Method of characterising an LED device
US9271370B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2012 |
| Grant date | Feb 23, 2016 |
| Priority date | — |
| Expiry date | Nov 10, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/2642
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of characterizing an LED, as well as an integrated circuit using this method, based on a so-called characteristic resistance, in which the LED is operated at a first, relatively low, operating current and then at a second, relatively high, operating current. From the ratio between the difference between the forward voltages at these two operating currents, and the difference between the operating current, the characteristic resistance is determined. The characteristic resistance is measured at two or more moments during the operational lifetime of the device, and a prediction or estimate is made in relation to the total operational lifetime of the devices, from the evolution or change of the characteristic resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.